Volume 16, Number 8—August 2010
Research
Multiyear Surveillance for Avian Influenza Virus in Waterfowl from Wintering Grounds, Texas Coast, USA
Table A1
Apparent prevalence of avian influenza virus in various waterfowl and wetland-associated game bird species as determined by VI and real-time RT-PCR from cloacal swabs collected from hunter-harvested waterfowl, Texas mid–Gulf Coast, USA, September 2006–January 2007*
Species |
No. tested |
Real-time RT-PCR,†
no. (%) |
VI,† no. (%) |
Isolate‡ |
American wigeon (Anas americana) | 171 | 4 (2.3) | 0 | – |
Fulvous whistling duck (Dendrocygna bicolor) | 18 | 2 (11.1) | 1 (5.6) | H6N1 |
Lesser scaup (Aythya affinis) | 60 | 1 (1.7) | 1 (1.7) | H10N7 |
Mallard (Anas platyrhynchos) | 5 | 1 (20.0) | 0 | – |
Mottled duck (Anas fulvigula) | 33 | 2 (6.1) | 1 (3.0) | H6N5 |
Northern pintail (Anas acuta) | 72 | 5 (6.9) | 0 | – |
Northern shoveler (Anas clypeata) | 360 | 23 (6.4) | 5 (1.3) | H2N9, H3N8, H4N2, H4N6, H4N8 |
Redhead (Aythya amercana) | 51 | 2 (3.9) | 0 | – |
Ring-necked duck (Aythya collaris) | 35 | 1 (2.9) | 0 | – |
Ruddy duck (Oxyura jamaicensis) | 31 | 2 (6.5) | 0 | – |
Teal, blue-winged (Anas discors) | 610 | 65 (10.7) | 19 (3.1) | H1N1, H2N9, H3N6, H3N8 (6), H4N2, H4N6, H4N8, H6N1 (3), H6N1/4, H6N5, H6N6, H6N8 |
Teal, green-winged (Anas crecca) | 358 | 31 (8.7) | 5 (1.4) | H1N1, H6N2, H7N3, H10N7, H11N3 |
Snow goose (Chen eaerulescens) |
46 |
2 (4.4) |
0 |
– |
Total§ | 2,171 | 141 (6.5) | 32 (1.5) | – |
*VI, virus isolation; RT-PCR, reverse transcription–PCR.
†Number positive (apparent prevalence). Numbers and apparent prevalences for VI are after RT-PCR result.
‡Isolates typed by the National Veterinary Services Laboratory. Included are VI that were RT-PCR negative on the original sample.
§Other species sampled that were negative for AI by RT-PCR and VI, number sampled: American coot (Fulica americana), 25; black-bellied whistling duck (Dendrocygna autumnalis), 6; bufflehead (Bucephala albeola), 2; canvasback (Aythya valisineria), 16; cinnamon teal (Anas cyanoptera), 1; common goldeneye (Bucephala clangula), 1;common moorhen (Gallinula chloropus), 1; common snipe (Gallinago gallinago), 1; gadwall (Anas strepera), 247; greater white-front goose (Anser albifrons), 3; hooded merganser (Laphodytes cucullatus), 11; mottled duck x mallard hybrid (Anas fulvigula x Anas platyrhynchos), 1; Ross’s goose (Anser albifrons), 2; sandhill crane (Grus candensis), 1; wood duck (Aix sponsa), 1; and unidentified teal, 2.